Electrical welding generators generally comprise an electrical motor and cooperating motor stator to drive a generator for the generation of a high welding current. The current developed from turning of the generator is usually passed on to a commentator which in turn communicates the current to the welding apparatus through brushes. Some of the present day commercial welding generators mount the motor rotor, generator rotor and commentator on the same shaft. The motor stator surrounds the motor rotor while a generator housing holds pole pieces which are mounted around the generator rotor. The axle is supported on each end by bearings and may even carry cooling fans at one or both ends. A housing is then placed around the entire working apparatus to keep the apparatus free from dust and the like.
The pole pieces which are force-fitted into the generator rotor housing are surrounded by electrical windings. The purpose of having a forced fit is to insure that a low reluctance path will be realized by the magnetism induced by the electrical windings. Oftentimes the pole pieces will be destroyed due to equipment breakdown. When this occurs their removal is necessary and is generally achieved by a pull-down of nearly the entire apparatus which usually includes pulling of the axle containing the motor rotor, generator rotor and commentator. This near complete pull-down is time-consuming and thus expensive.
Therefore it is an object of this invention to provide an apparatus which allows for the pulling of force-fitted pole pieces from generator housings which does not require a near complete pull-down of the electrical welding apparatus.
This invention relates to an apparatus for pulling a tight-fitting pole piece from a housing which apparatus comprises: a first plate having at least two first plate apertures therethrough; contact means for contacting the pole piece; at least two substantially parallel elongated force transmittance means attached at one of their ends to the contact means and passing through said apertures; connecting the force transmittance means at their other ends; and force means contacting the plate on that side of the plate opposite the contact means and contacting the connecting means whereby an outward force applied by the force means causes the connecting means to move away from the plate and the contact means to move towards the plate.
The apparatus of this invention may also include optional additional plates which overlie the first plate. These additional plates are utilized to receive different sized force means, adjust the spacing distance between the force transmittance means and to lend extra strength to the first plate. Different sized force means and adjustment of the spacing distance is of importance when the apparatus of this invention is used on various sized pole pieces which various pieces require more or less pulling force for their removal and different spacing for a proper fit.